Planetary Health Research Digest
Authors: Sam Hinsley
Journal: The Lancet Planetary Health (2021)

Increased frequency of extreme precipitation events has been suggested as one way that climate change has already impacted the world, with such events linked to increased flooding. However, the degree to which short-term rainfall events affect flood damages is not clear. Frances Davenport (Stanford University, USA) and co-authors used historical data from the 1988 to 2017 to evaluate the association between rainfall (monthly mean and 5 day maximum) and flood damages in the US and found a significant positive association, estimating that about 36% of flood damages in this period (US $73 billion) were the result of historical precipitation changes. Using climate models, they showed anthropogenic climate forcing to increase the probability of the most extreme precipitation events responsible for the majority of the damage. Linking their results to future greenhouse gas emission scenarios, they suggest that further increases in damage resulting from floods could be reduced in a more ambitious emission control scenario. Evaluating the costs of climate change from such natural hazards is crucial for assessing the true costs and benefits of mitigation options. The Australian bushfire season of 2019–20 was the worst on record, with fires of an unprecedented scale and intensity burning across southeast Australia from September, 2019, to February, 2020. Some past climate assessments predicted that the impacts of anthropogenic climate change on the number high fire risk days in Australia would already be detectable by 2020, although others suggested that the impacts would take longer to manifest. Nerilie Abram (Australian National University, Australia) and co-authors investigated how climate factors came together to result in such extreme fires. They found that the probability of days with a high risk of fire has already moved above the range of historical experience, as a result of long-term climate change trends and more frequent alignments of the fire-promoting phases of different forms of climate variability such as the Indian Ocean Dipole and Southern Annular Mode. Paleoclimate analyses suggested that these alignments are now more common than would be expected from natural, pre-industrial climate variability alone. The authors conclude that the unusually severe fire season was very likely a result of human-induced climate change, making ambitious adaptation and climate change mitigation measures essential to limiting devastation from future fires. Interventions to promote climate change adaptation aim to reduce vulnerability for the people receiving them, but they can have unintended consequences. Siri Erksen (Norwegian University of Life Sciences, Norway) and co-authors reviewed internationally funded interventions to promote climate change adaptation to characterise the ways that they can inadvertently promote vulnerability. Central to the challenges involved is the failure of many adaptation interventions to take account of existing power structures and meaningfully engage with already marginalised groups. As a result, interventions may end up reinforcing or redistributing existing vulnerabilities or even creating new sources of vulnerability. Furthermore, the retrofitting of adaptation into existing agendas and poor definitions of successful adaptation hinder the ability of these interventions to introduce the transformational change needed to address the unequal power structures perpetuating vulnerability. The authors argue that without critical interrogation of the politics of adaptation and the processes leading to vulnerability in the planning stage, adaptation interventions risk further entrenching the vulnerability of already marginalised groups. Although advocacy by researchers is often seen as a way to enhance public and policy engagement with issues related to climate change, there is a risk that being seen as advocates could undermine public trust in scientists. Viktoria Cologna (ETH Zürich, Switzerland) and co-authors conducted surveys of scientists researching climate change, as well as members of the public in the USA and Germany to investigate how climate change advocacy was perceived among the different groups. While perceptions varied, the majority of surveyed scientists and members of the public agreed that scientists should be advocates for policies related to climate change, with most of the members of the public agreeing that scientists should be more engaged. Notably, while openly supporting climate policies was seen as reducing the objectivity of researchers, this was not related to any change in their perceived honesty or trustworthiness. The results suggest that there is greater public support than expected for climate change researchers to get involved in policy discussions, and that many members of the public would encourage them to do so.